Pneumatic jack



July 31, 1923. 1,463.654

A. E. MCNULTY PNEUMATI C JACK Filed March 18, 1922 2 Sheets-Sheet 1 Zigl July 31, 1923.

A. E. M NULTY PNEUMATIC JACK Filed March 18 1922 2 Sheeis-Sheet 2 Patented July 31, 1923.

UNITED STATES ARTHUR E. KONUL'I'Y, OF BANGOR, MAINE.

PHEUIATIC JACK.

Application filed Iarch 1B, 1922. Serial 80. 544,708.

To all whom it may comm:

Be it known that I, An'rnun E. McNUL'rY, a citizen of the'United States, residing at Bangor, county of Penobscot, State of Maine, have invented certain new and useful Improvements in Pneumatic Jacks, of which the following is a specification.

This invention relates to lifting jacks, and consists in the novel construction, com bination and relation of parts described and illustrated in the accompanying specifica tion and draw' and particularly pointed out in the appe rir l ed claims.

One object of my invention is to provide a jack in which the movement of the lifting member will be effected through the agency of compressed air.

Another object is to provide a jack which may be conveniently applied to the axle of an automobile or other vehicle and by means of which the vehicle ma be raised with the minimum effort and wit out liability of the jack slipping from under the axle during the liftin action.

A further object is to provide a jack in which the lifting member will have a straight upward movement regardless of the position of the car, that is regardless of whether the car is on a level or a sloping surface.

Other objects are to provide a jack of simple and sturdy construction which will be efficient in action and in which the lifting member will be capable of shortening or lengthening adjustment as conditions may require.

These and certain other features ofadvantage which will appear more fully hereinafter are secured in the jack of the present invention.

The construction and operation of my 'ack together with a selected embodiment w ich well illustrates the principles involved, is described and shown in the accompanying specification and drawings, throughout which like reference characters are correspondingly applied. In the drawings:

Fig. 1 is a view of a jack in accordance with my invention in applied position upon the rear axle of an automobile.

Fig. 2 is a side elevation of the jack.

Fig. 3 is a longitudinal section thereof.

Figs. 4 to 8 inclusive are detail views of the lifting lug on the jack.

' Figs. 9 and 10 are detail views of parts,

'to the ground-engaging foot 16 may be of the jack piston, and

Figs. 10 and 11 are detail views of the axle socket for the lifting lug.

I have indicated at 1 a movable cylinder which is preferably provided between its ends with an annular recess 2, Fig. 3, within which is a ring 3 having a pro ecting rib 4. Detachably fastened at 5 to the rib 4 is a lifting lug or bracket 6. The lug 6 is preferably formed as a casting having a horizontal lifting surface forked at its inner end to receive the attaching rib 4 of the mounting rin 3. (See Fig. 4.) Below the horizontal li ing surface the lug 6 extends as a depending bracing portion 7 of inverted V-form.

The upper face of the lifting surface is preferabl rounded to fit within the correspondingy rounded recess 8 of a socket plate 9 (Figs. 10 and 11) which is bolted or otherwise fastened as indicated at 10 to the rear axle 11 of an automobile or other vehicle to be lifted. This construction provides an engaging surface with which the lifting member of the jack may be positively engaged without liability of the jack slipping from beneath the axle during the lifting action.

In the type of jack illustrated, the lifting lu 6 is raised upwardly with thecylinder, 1 y admitting compressed air into the cylinder against a piston 12 therein. The piston 12 consists of a cushioned head, and a stem 13 which as here shown is hollow and is internally threaded to engage the external threads 14 of a standard 15 disposed 'within said stem and terminating at its lower end in a flat-bottomed supporting foot 16. The threaded connection of the piston and stem and standard permits the jack to be lengthened or shortened as occasion requires by rotating the standard relative to the piston stem.

In order to prevent the piston stem from turning during such rotative adjustment, said stem is preferably provided with a longitudinally extending rib or flange 17 which is disposed in a slot cut in the bottom closure 18 of the cylinder, said closure having screw-threaded connection at 19 with the cylinder wall.

Air under pressure is admitted into the cylinder above the piston head through an air connection 20, and below the piston head said cylinder has an air vent opening 21, Fig. 3. The height of the air vent relative a mounting member fixed thereto and having a rib a. lifting member detachably connected varied according to the size and displacement of the piston.

The piston head is cushioned as best ind catcd in Fig. 3. Referring to this fi c, it will be noted that the upper end of t e cylinder carries a resilient cushio element 23 on its under face, and that e piston itself is provided with a cupped cushioning element 24 opposing the cushioning element 23 and fastened to a block 25 which is 'eldingly supported by coil springs 26 an steel washer 26' on a cushioning element 27 resting on the head 28 of the piston stem 12. In addition to the cushioning effect thus provided, the piston head, of course, prevents the passage of the air past the piston, the cylinder is accordingly raised in a straight line direction on the piston, regardless of the position of the car, that is regardless of whether the case is on a level or a sloping surface.

In use, the jack is lengthened or shortened as required by manually rotating the standard 15 relative to the piston until the lifting lug 6 is brought closely beneath the socket 9 of the car axle. When compressed air is admitted into the cylinder, the cylinder is thereby raised relative to the piston, thus elevating the car.

Various modifications in the construction and operation of my device may obviously be resorted to without departing from the spirit of my invention if within the limits of the ap nded claims.

What therefore claim and desire to secure by Letters Patent is:

1. A jack comprising a movable element,

to said mounting member and comprising a horizontally disposed lifting surface forked at its inner end to straddle said rib and having a depending bracing portion.

2. In a jack for use with a vehicle having a recessed socket, a movable cylinder, a mountin ring fixed thereto and having a rib, a 1i ing member detachably connected to said ring and comprising a horizontally disposed lifting surface adapted to enter the recess of said socket and forked at its inner end to straddle said rib and having a depending bracing portion of inverted V-form.

3. A jack comprising a cylinder having an air connection, a lifting member carried thereby, a hollow piston stem within said c linder having a head closely fitting against e cylinder wall,a footed supporting standard mounted within said stem and having screw threaded connection therewith permitting the standard to be lengthened or shortened upon rotation thereof relative to said stem, and a longitudinally disposed flange on said stem engaging said cylinder for preventing rotation of said stem within said cylinder.

4. A jack comprising a cylinder having an air connection, a lifting member carried thereby, a piston stem within said cylinder having a head closely fitting against the cylinder wall, and a cushion between said head and the adjacent end of the cylinder comprising a pair of opposing cushioning elements and a yieldable support for one of said cushioning elements mounted upon said piston head.

5. A jack comprisin a cylinder having an air connection, a li ting member carrie thereby, a hollow piston stem within mid cylinder having a head closely fitting against the cylinder wall, a footed supporting standard mounted within said stem and having screw threaded connection therewith permitting the standard to be len hened or shortened upon rotation thereo relative to said stem, a longitudinally disposed flange on said stem e ging said cylinder for preventing rotation of said stem within said cylinder, and a cushion between said head and the adjacent end of the cylinder comprising a pair of opposing cushioning element and a yieldable support for one of said cushioning elements mounted upon said piston head.

6. A jack comprising a cylinder having an air connection, a mounting ring fixed thereto and having a rib, a lifting member detachably connected to said ring and comprising a horizontally disposed lifting surface forked at its inner end to straddle said rib and having a depending bracing portion of inverted V-form, a hollow piston stem within said cylinder having a head closely fitting against the cylinder wall, a standard mounted within said stern and having screw threaded connection therewith permitting the standard to be lengthened or shortened upon rotation thereof relative to said stem, and a longitudinally disposed flange on said stem engaging said cylinder for preventing rotation of said stem within said cylinder.

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR E. MoNULTY. lVitnesses:

DANA B. Bacon, Errm A. SMITH. 

